With ever increasing demand for communication services, and the crowding of conventionally assigned spectrum, governments are allowing unlicensed communication operation in licensed, but under-utilized spectrum bands. One example of this is the recent Federal Communications Commission's decision to allow radio communication systems to use channels in the spectrum region designated for licensed television broadcast. In a given geographic region, there will typically be a number of television channels which are not presently being utilized for television transmission. These unused wideband 6 MHz channels may be made available for narrowband radio communication which may be 12.5 KHz to 150 KHz wide. Accordingly, there is a need to identify spectrum segments or channels conventionally licensed or utilized for one form of communication that may be used for alternative communication activity.